What is the vitreous?
It is the clear, gel-like substance which fills the main cavity of the eye.


The vitreous humour makes up most of the volume of the eye.


What are floaters?
When we are born, the vitreous gel is relatively firm, and fills the whole vitreous cavity, meaning that it is in contact with (but not normally stuck to) the retina. As we age, the vitreous gel gradually liquefies and collagen dissolved in the gel can condense to form a few small strands which float inside the vitreous. These cast shadows on the retina, which are perceived as floaters. Consequently, a few small floaters can occasionally develop in young adulthood and are usually nothing to worry about.

What is posterior vitreous detachment (PVD)?
Between the ages of around 40-80 years, the vitreous gel can collapse quite quickly away from the retina and form a smaller ball of gel in the middle of the vitreous cavity. This process is called PVD (posterior vitreous detachment) and it is a normal age-related process that probably occurs in most eyes at some point.

What are the symptoms of PVD?
PVD often causes no symptoms at all, but in some eyes it can cause a perception of fleeting flashes of light in the outside of the field of vision, often followed by sudden onset of (or increase in) floaters. Some patients only get the flashes or the floaters, but not both. All patients with these symptoms should undergo detailed examination of the retina in order to exclude a retinal break or retinal detachment.

Are there any complications of PVD?
In most people, the vitreous separates from the retina without causing any problems. In a small number of patients, the vitreous can pull on and break either a retinal blood vessel (which can cause vitreous haemorrhage) or the retina itself, causing a retinal break or retinal detachment. This is why all patients with these symptoms should undergo detailed examination of the retina in order to exclude a retinal break or retinal detachment.

Will the flashes of light go away?
The flashes of light are always in the outer field of vision of the affected eye and are very brief, like camera flashes. They are noticed more in the dark, for example at night. They may be brought on, or worsened, by head movement or eye movement. In most patients, the flashes gradually disappear over time, but in a small minority, they can occasionally persist. Where they persist, there is usually no cause for concern.

Will the floaters go away?
Floaters following PVD remain in the eye, so they technically don’t go away, but people usually become less aware of them over time. Most people are no longer bothered by floaters around 2 months after PVD onset.

Can the floaters be removed?
Yes, with a procedure called a vitrectomy, but most PVD patients do not need this to be done because the floaters quickly become less bothersome. There is more information on the pages about floaters and vitrectomy.